Lymphoma is a type of blood cancer that develops when white blood cells called lymphocytes grow out of control. Lymphocytes are part of our immune system. They travel around our body in our lymphatic system, helping us fight infections. There are two types of lymphocyte: T lymphocytes (T cells) and B lymphocytes (B cells).
Lymphomas can be grouped as Hodgkin lymphomas or non-Hodgkin lymphomas, depending on the types of cell they contain. T-cell lymphomas are non-Hodgkin lymphomas that develop from T lymphocytes.
Most T-cell lymphomas develop from mature T cells. They usually affect older adults, typically people in their mid-60s. They are more common in men than in women. Occasionally, T-cell lymphoma can develop from immature T cells. This is known as T-cell lymphoblastic lymphoma. It tends to affect children and young adults.
In most cases, it is not known what causes T-cell lymphomas. In a few types of T-cell lymphoma, research has shown that certain viral infections or medical conditions can increase the risk of developing lymphoma.
Human T-lymphotropic virus type 1 (HTLV-1) is linked with development of adult T-cell leukaemia/lymphoma (ATL).
Past infection with Epstein-Barr virus (EBV) is linked to the development of a range of lymphomas, including angioimmunoblastic T-cell lymphoma (AITL).
Enteropathy-associated T-cell lymphoma (EATL) is linked with coeliac disease.
Relapsed refers to when a patient has received active treatment, went off treatment and then the disease came back, whereas refractory refers to disease that is progressing despite active treatment.